Junk basket for well bores



July 14, 1959 R. c. BAKER 2,894,725

y JUNK BASKET FOR WELL BORES Filed July 2o, 195s United States Patent C F JUNK BASKET FOR WELL BORES Reuben C. Baker, Coalinga, Calif., assignor to Baker lOil Tools, Inc., Los Angeles, Calif., a corporation of California Application July 20, 1956, SerialI No. 599,259 Claims. (Cl. Z55-28)' The present invention relates to subsurface well bore equipment, and more particularly to apparatus for facilitating the drilling out of devices and materials in the well bore.

Certain kinds of devices are permanently secured in the well bore. After they have served their purpose it is customary to remove them, which usually is performed through use of a drill bit. The particular device being drilled out or disintegrated by the drill bit may be made from readily drillable materials, such as cast iron, aluminum alloy, bronze, and the like, which may be diicult to circulate from the well by the drilling fluid being pumped down through the drill pipe and the drill bit. Accordingly, a junk basket has heretofore been used above and adjacent to the drill bit, to catch and entrap the metallic and other relatively heavy pieces or particles produced by the drill bit, the drilling weight and torque being transmitted from the string of drill pipe extending to the top of the hole, through the junk basket, to the drill bit.

Heretofore, junk baskets would sometimes twist off, or otherwise fail, when subjected to comparatively heavy drilling torques and other loads. As a result, care had to be exercised to avoid subjecting the basket to high stresses, which stresses could be safely withstood by the drill pipe and the drill bit itself, retarding the drilling out of the device in the well bore, which necessarily involved a greater cost of operation.

Accordingly, it is an object of the present invention to provide a junk basket to be incorporated in a drill string, which is capable of withstanding substantially high torque loads and drilling weight, the basket still being capable of entrapping and containing a comparatively large quantity of metallic and other cuttings.

Another object of the invention is to provide a junk basket which not only has a high torque transmitting capacity, but from which cuttings can be removed easily when the basket has been elevated to the top of the hole.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of several forms in which it may be embodied. Such forms are shown in the drawings accompanying and forming part of the present specication. These forms will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

. Referring to the drawings:

Figure 1 is a longitudinal section through a form of the invention disposed in a well bore;

Fig. 2 is a cross-section taken along the line 2-2 on Fig. l;

Fig. 3 is a cross-section taken along the line 3-3 on Fig l;

Fig. 4 is a fragmentary longitudinal section through a modified form of junk basket.

2,894,72 Fatented July 14,V 19,59

ICC

As illustrated in the drawings, a junk basket A isse cured to a string of drill pipe B extending to a top of a well bore C. The junk basket, in eiect, actually conf stitutes part of the drill string being secured, directly or indirectly, to a drill bit D which is to operate upon a device or material E disposed in the well bore, such as` a well packer or cement, which has previously been permanently anchored in well casing F disposed in the well. bore and extending to the top thereof. The junk basket A is provided to catch and retain pieces that have. been, disintegrated by the drill bit as they are flushed, by the. drilling fluid, such as drilling mud, upwardly around the, junk basket to its upper end. I

As disclosed in the drawings, the junk basket includes. a tubular mandrel 10 provided with a threadedy pin 11 threadedly secured to the lower box 12 of a.y drill pipe. section B, or a drill collar, forming part of the drilling string extending to the top of the hole, and by means of which the apparatus A and the drill bit D therebelow are rotated and drilling fluid circulated in the well casing-` or well bore. The lower portion of the junk basket conf sists of a lower closure member 13 which has a. threaded box 14 adapted to be threadedly secured to the pin end, 15 of the drill bit (of any desired type) having cutters 16 adapted to operate upon and disintegrate the wellv packer E or other substance secured in the well casing F. The closure member 13 forms the llower end of `al container structure adapted to receive and retain the bitcuttings. As shown, the upper portion of the closure. member is constituted as a threaded pin 17 threadedly secured to the lower internal thread 18 of a cylinder orhousing 19 extending upwardly from the closure mem-` ber 13 to the desired length o-r height. The upper pori tion of the cylinder 19 surrounds the lower portion 2.0l of the tubular member or mandrel 1t) which is substantially reduced in external diameter as compared to the upper portion 21 of the mandrel adjacent the drill pipe B. This upper portion has an upwardly facing shoulder 22 adapted to engage the lower end of the drill pipe or drill collar B.

The drilling torque is transmitted from the drill pipe B to the tubular mandrel 10 and to the sub or lower closure member 13 by way of a plurality of ribs 23 andthe cylinder 19. The ribs are integral with the reduced diameter portion 20 of the tubular mandrel 10, extending outwardly into slots 24 in the upper end of the ylini der 19, where the outer portions of the ribs are inteV` grated to the cylinder, as through use of welding mater"V vrialV 25. The ribs 23 themselves extend outwardly of the axis of the mandrel to substantially the same extent as the shoulder portion 21, 22 of the mandrel, com= mencing at such shoulder portion and extending down# wardlywithin the upper portion of the cylinder 19 to the lower end of the tubular mandrel 10. The upper.

end 19a of the cylinder 19 is spaced below the circum-A ferentially continuous shoulder portion 21 of the tubular mandrel by a substantial extent to provide ample space between the enlarged portion 21 and the upper end of the cylinder through which cuttings can enter the arcuate spaces 26 between the ribs 23 and then drop downwardly into the cylinder 19. The lower end 10a of the tubular mandrel 10 is disposed a substantial distance above the upper end `of the closure member 1-3 so as to provide circumferentially uninterrupted space 27 within the cylinder 19 for the accumulation and retention of the cuttings. Y

The circulating fluid being pumped down the dril pipe passes through a central lluid passage 28 in the tubular mandrel 1t! and then through a conductor tube 29 having its upper end piloted within a lower counterbore 30 in the mandrel and its lower end within an up-V per oounterbore 31 in the lower closure member or sub` 13. The conductor tube 29 has a fluid passage 32 completely therethrough through which the drilling uid can ow, continuing on through the central passage 33 of the closure member 13 and into the fluid passage 34 in the drill bit D, the fluid discharging from the latter to carry the cuttings away from the drilling region and upwardly around the drill bit D and the junk basket A itself. The uid passages 28, 32, 33 through the tubular mandrel 10, conductor tube Z9, and the closure member or sub 13 are preferably unrestricted, so as to permit comparatively large volumetric rates of drilling mud, or other uid, to be pumped through the apparatus. As assurance that such fluid cannot leak around the conductor tube 29, suitable side seal rings 35 may be provided in suitable peripheral grooves 36 in the upper portion of the conductor tube to sealingly engage against the Wall of the mandrel counterbore 30. Suitable side seal rings 37 may also be disposed in internal grooves 38 in the closure member 13 to sealingly engage the periphery of the lower portion of the conductor tube 29.

In the operation of the apparatus, the drill pipe B is rotated, the turning elort being transmitted through the tubular mandrel and its ribs 23 to the cylinder 19, proceeding from the latter through the closure member 13 to the drill bit D therebelow. The drill bit is thereby rotated while appropriate drilling weight is imposed thereon, fluid being circulated down through the drill pipe B and the uid passages 28, 32, 33 in the apparatus for entry into the drill bit passage 34 and discharge from the drill bit. The fluid carries the cuttings, which may be in the form of relatively small pieces or particles, upwardly around the drill bit D, and up through the annulus 39 around the lower sub 13 and the cylinder 19, the fluid and the cuttings moving at a relatively high velocity because of the comparatively small annular area between the periphery of thc lower sub and cylinder 13, 19 and the wall of the well casing F. The fluid and the cuttings reach a region 40 immediately above the upper end 19a of the cylinder or container 19, wherein ythe cross-sectional area between the tubular mandrel 10 and the wall of the well casing F is considerably increased with respect to the annular area 39 around the cylinder 19 itself. This causes the velocity of the fluid and cuttings to decrease substantially, reducing the carrying power of the circulating fluid, the metallic cuttings dropping through the opening 41 defined between the upper cylinder portion 21 of the mandrel 10 and the upper end 19a of the basket 19 into the arcuate spaces Z6 between the ribs and then downwardly into the container 19, the cuttings being supported upon the upper end of the sub 13. To prevent the drilling fluid in the con- -tainer from impeding the gravitating of the cuttings toward the bottom of the container, the lower portion of the cylinder 19 immediately above the sub 13 is provided with a plurality of drain holes or openings 42 through which the drilling fluid can be displaced.

The drilling action proceeds until the device E being operated upon is fully disintegrated, the container preferably having a capacity to hold substantially all cuttings that arrive at the region of the openings 41, so that a single drill bit D and basket A combination is effective to remove the device E, such as a well packer, from the well casing F with a single round trip in the well bore.

After the operation in the well bore has been completed, the drill pipe B, junk basket A and drill bit D are elevated and removed entirely from the hole. The junk basket A is then disconnected from the drill pipe B and the drill bit D, whereupon the threaded sub or closure 13 can he unscrewed from the cylinder 19 to permit the contents of the cylinder to drop from its lowerend. In this regard, it is noted that a straight threaded connection 17, 18 is provided between the upper end of the closure member 13 and the lower end of the cylinder 19 so that no portions of the cylinder project inwardly of its inner wall, against which the cut- 1 tings may tend to pack, hampering ready discharge of the cuttings from the cylinder.

In the form of the invention disclosed in Fig. 4, the lower portion of the conductor tube 29a is also piloted within the counterbore 31 in the closure member, the rubber or rubber-like seal ring 37a lbeing mounted in a peripheral groove 38a in the lower portion of the conductor tube, and sealingly engaging the wall of the counterbore. To provide a stronger threaded connection than is shown in the other form of the invention, the lower end 18a of the cylinder 19h is thickened materially in cross-section, being constituted as a box having an internally tapered thread 13b coacting with a companion tapered threaded pin 17a on the closure member 13a. In effect, the threaded pin 17a and box 15a are designed as a tool joint of the same character as the threaded connection 12, 11 between the drill pipe B and mandrel 10, and between the closure member 13a and the drill bit D, the lower end 19C of the cylinder engaging a companion shoulder Sil on the closure member. A much greater drilling torque can be transmitted through the tapered threaded connection 17a, 18a illustrated in Fig. 4 than through the corresponding threaded connection shown in Fig. l. l

In all respects, the modified form of apparatus shown in Fig. 4 operates in the same manner as the one illustrated in Figs. l to 3, the torque being transmitted from the tubular mandrel 16 to the cylinder 19b, and then through the threaded connection 18a, 17a to the lower closure member 13a, from where it is transferred to the rotary dril bit D.

By virtue of the constructions illustrated, the drilling torque is transmitted from the tubular mandrel 10, which has a large torque transmitting capacity because of its cross-sectional area including the relatively great crosssectional area of its radial ribs 23, to the cylinder, to which it is rigidly connected along a substantial length of ribs 23, the cylinder having a comparatively large wall thickness and diameter, and thereby providing a large cross-sectional area through which the drilling torque can be carried to the large cross-sectional area lower closure member 13 and then to the drill bit. By transmitting torque from the tubular mandrel 19 through the cylinder or container 19 and the lower closure member 13 to the drill bit D, the junk basket has a much greater torque transmitting capacity than in prior devices, which did not transmit the torque through the cylinder member. Despite the fact that the torque is transmitted through the cylinder portion of the apparatus, the latter still possesses a large capaciy for the drill bit cuttings that can readily enter the container 19 as the fluid velocity and carrying power of the liuid decreases in the region 40 around the inlet openings ill in to the apparatus between the upper portions of the ribs 23.

The inventor claims:

l. In a junk basket to be disposed above and secured to a rotary drill bit: a tubular mandrel adapted to be connected to a drill string to be disposed in a well bore; a cylinder encompassing said mandrel and having an upper terminus substantially below the upper end of said mandrel; circumferentially spaced, lateral ribs extending substantially below said upper terminus and attaching said mandrel to said cylinder, said ribs extending substantially above said upper terminus and providing inlet openings therebetween through which debris can pass downwardly into said cylinder; and means secured to and closing the lower portion of said cylinder and adapted to be connected to the rotary drill bit, whereby drilling torque can be transmitted from said mandrel through said ribs to said cylinder, and then through said closing means to the drill bit.

2. In a junk basket to be disposed above and secured to a rotary drill bit: a tubular mandrel adapted to be connected to a drill string to be disposed in a Well bore; a cylinder encompassing said mandrel and having an upper terminus substantially below the upper end of said mandrel; circumferentially spaced, lateral ribs extending substantially below said upper terminus and attaching said mandrel to said cylinder, said ribs extending substantially above said upper terminus and providing inlet openings therebetween through which debris can pass downwardly into said cylinder; means secured to and closing the lower portion of said cylinder and adapted to be connected to the rotary drill bit, whereby drilling torque can be transmitted from said mandrel through said ribs to said cylinder, `and then through said closing means to the drill bit; said closing means having a iluid passage; and tubular means in said cylinder extending between said mandrel and closing means to conduct iluid from said mandrel to said closing means.

3. In a junk basket to be disposed above and secured to a rotary drill bit: a tubular mandrel having a passage and adapted to be connected to a tubular string to be disposed in a well bore; a cylinder encompassing said mandrel and having an upper terminus substantially below the upper end of said mandrel; circumferentially spaced, lateral ribs integral with said mandrel and extending downwardly into land attached to said cylinder, said ribs extending substantially above said upper terminus and providing inlet openings therebetween through which debris can pass downwardly into said cylinder; means secured to and closing the lower portion of said cylinder and adapted to be connected to the rotary drill bit, whereby drilling torque can be transmitted from said mandrel through said ribs to said cylinder, and then through said closing means to the drill bit; said closing means having a passage; and tubular means disposed in said cylinder in spaced relation thereto and piloted within said mandrel and closing means passages to conduct drilling fluid from said mandrel passage to said closing means passage.

4. In `a junk basket to be disposed above and secured to a rotary drill bit: a tubular mandrel having a passage and adapted to be connected to a drill string to be disposed in a well bore; a cylinder encompassing said mandrel and having an upper terminus substantially lbelow the upper end of said mandrel; circumferentially spaced,

lateral ribs extending substantially below said upper terminus and attaching said mandrel to said cylinder, said ribs extending substantially above said upper terminus and providing inlet openings therebetween through which debris can pass downwardly into said cylinder; a sub threaded into the lower end of said cylinder to close the same and adapted to be connected to the rotary drill bit, whereby drilling torque can be transmitted from said mandrel through said ribs to said cylinder, and through said sub to the drill bit; said sub having a iluid passage; and tubular means in said cylinder extending between said mandrel and sub passages to conduct uid from said mandrel passage to said sub passage.

5. In a junk Ibasket to be disposed above and secured to a rotary drill bit: a tubular mandrel having a passage and adapted to be connected to a tubular string to be disposed in a well bore; a cylinder encompassing said mandrel and having an upper terminus substantially below the upper end of said mandrel; circumferentially spaced, lateral ribs integral with said mandrel and extending downwardly into and attached to said cylinder, said ribs extending substantially above said upper terminus and providing inlet openings therebetween through which debris can pass downwardly into said cylinder; a sub threaded into the lower end of said cylinder to close the same and adapted to be connected to the rotary drill bit, whereby drilling torque can be transmitted from said mandrel through said ribs to said cylinder, and then through said sub to the drill bit; said sub having a passage; `and tubular means disposed in said cylinder in laterally spaced relation thereto and piloted within said mandrel and sub passages to conduct drilling fluid from said mandrel passage to said sub passage.

References Cited in the le of this patent UNITED STATES PATENTS ,1,525,235 Hansen Feb. 3, 1925 1,656,526 Lincoln Jan. 17, 1928 2,665,766 Harlin Ian. 12, 1954 

